Medical Officers provide immunisation services. Immunisation is one of the most cost-effective ways of reducing childhood morbidity and mortality. They may provide a specialist child health clinic for development problems in children with physical, sensory and intellectual disability. They carry out the medical assessment of grants and allowances administered by the HSE, County Councils and Revenue Commissioners and an Allowances Appeals process for those deemed non-eligible. They provide medical assessment for long term illness cards, over scale medical cards and hardship drugs.

In some areas Medical Officers provide targeted community medical services for socially excluded groups such as refugee/asylum seekers, travellers and the homeless.